摘要:
A connection element (1) has a thread (2) that can be made to engage with a mating thread such as, for instance, a nut. The thread includes locking means (3) that acts upon the mating thread. The locking means (3) are formed by flanks (4, 5; 6, 7, 8, 9) of at least one section (10; 11) of the thread (2) whose arrangement with respect to each other is changed vis-à-vis the arrangement of the flanks (18, 19) of the thread (2) outside of the locking section (10; 11) in such a way that, when the thread (2) engages with the mating thread, a locking force is generated on at least one of the flanks (4, 5; 6, 7, 8, 9) of the locking section (10; 11).
摘要:
Screw provided with self-locking rolled thread, wherein, in a plurality of places along its extent, the thread is deformed in relation to the normal thread cross section in that the thread outside diameter is reduced by radial compression of limited thread portions, the area of the thread cross section being substantially identical to that of the undeformed thread. While maintaining the slant of the thread flanks, the thread cross section is symmetrically widened in the outer region and reduced in the adjoining inner region, the transition from the widened to the reduced thread cross section lying approximately in the centre of the respective thread flank, and the limited thread portion extends over two parts of a thread turn such that there result two symmetrically opposite thread portions each of approximately ⅙ of the thread turn.
摘要:
In a nut disengagement prevention structure, a bolt has an external thread. A nut which is thread on the bolt has an internal thread. A thread portion which is the closest to a leading end of the bolt has a first minor diameter. Any other portion of the thread of the bolt has a second minor diameter which is smaller than the first minor diameter. The second minor diameter is substantially identical with a minor diameter of the internal thread of the nut.
摘要:
A male screw which has a protrusion protruding from a thread thereof at least with regard to the normal direction to a flank of the thread. To obtain such male screw, a blank is introduced between rolling dies which are moved relative to one another and is rolled between the rolling dies to be formed with a thread. In this thread rolling process, the rolling pressure on an area of a die face of at least one of the rolling dies is determined to be higher than that in an ordinary thread rolling process and the rear end portion of the area of the die face is made to bite into the blank, causing the corresponding portion of the blank to be forced out to form the protrusion.
摘要:
A prevailing torque fastener comprising an externally threaded shank having a locking portion comprising a displaced thread segment including an offset root and a correspondingly offset crest. When engaged with a mating internal thread, the locking portion causes the mating thread to deform at its minor diameter with little or no deformation at its pitch or major diameter.
摘要:
The axle of a bicycle wheel hub is formed with a screw thread to be engaged by the internal threads of a complementarily threaded bearing cone, and certain threads of the axle are modified in a particular manner to produce binding means highly effective for automatically and releasably locking the bearing cone at selected locations upon the axle, for the purpose of maintaining a reliable anti-friction bearing adjustment.
摘要:
A thread rolling die and a method of manufacturing such die is disclosed for forming self-locking threads having helically arranged arrays of thread form projections. The dies include thread forming convolutions spaced along the length of the die by a distance equal to pi times the diameter of the blank to be threaded. Projection forming troughs are formed in the die at spaced locations along the length of the die a distance biased upon pi times the sum of the blank diameter and two times the height of the projections. In the illustrated embodiment wherein three arrays of projections are provided around the thread to be formed, the spacing of the troughs is pi divided by three times the sum of the blank diameter plus two times the height of the projections. The troughs are formed by a shaped pressing tool which is pressed into the face of the die prior to hardening wherein the spacing is arranged as set forth.
摘要:
A self-locking fastener in which a portion of less than 180* circumferential extent of the screw thread of the fastener is changed in pitch diameter to achieve an interference fit. If it is an external screw or male thread, it is increased in pitch diameter; but if it is an internal screw or female thread, it is decreased in pitch diameter. In both instances, the cross sectional width of the screw thread is increased at any given diameter, and the width of the crest of the screw thread is increased without change in the crest diameter of the screw thread. In addition, improved locking is obtained, particularly at relatively high temperatures, by constructing the portion as an insert of a metal having a coefficient of expansion which is substantially the same or higher than the material of the fastener.
摘要:
A thread is rolled on the bolt blank around a predetermined length thereof, and during the thread-rolling operation the bolt is indented at diametrically opposed parts of its threaded length, to give a portion of this length a generally elliptical cross section which is near but spaced from the leading end of the bolt. The indented portion surrounds a central axial bore which opens through the leading end of the bolt, the bore diameter being 0.35D to 0.50D and the bore length being about 1D, where D is the nominal outer diameter of the thread on the bolt. The pitch diameter of the thread on the major axis of the elliptical cross section is slightly greater than the normal pitch diameter above the elliptical section, such as about 1.03 times the normal pitch diameter, to provide the self-locking action. Thus the friction which causes the self-locking action occurs along the flanks of the threads, rather than at the crests and roots.